CompuServe Messages

Distinctions between 24 bit, 21 bit, 18 bit (all RGB) and NTSC are not pointless, in my view. There are several reasons. First, 24 bit output is a specific level of accuracy; much like RMS, IHF, Peak, Instantaneous Peak power of the old stereo ad claims, where the number of "watts" a stereo had was the [ill-informed] consumers index of what stereo to buy; where the definition of "watts" was being quite loosely dropped on (initially) unsuspecting consumers. 24 bit accuracy indicates that you can develop 256 _distinct_ grey levels; it means that you have a rather large dynamic range for "difficult" colors such as flesh tones; it also implies that the color representation of the "device" is good enough that the resulting images are capable of representing color better than you can percieve it. As a marketing line, 24 bit color means to the consumer that they are getting "the best". Composite output, far from being the best, is nearly the worst of all – although it has a large (approximately 20 bit) dynamic range for color, it has _horrible_ dynamic color change response, so bad that _anybody_ can spot color errors in almost any image that has any red or blue in it. It is in fact virtually impossible with an accurate studio monitor, aligned to spec and as noise free as possible analog NTSC encoding/decoding equipment to resolve 24 bits of color information from a signal that is only a few tenths of a volt and mashed in there with numerous other pices er, pieces, of information all running at very high speed. So when NewTek and Digital Creations say 24 bit, it's _wrong_. If we leave the studio with it's engineers and vector scopes, the odds of an NTSC system getting anywhere NEAR 24 bit accuracy go out the window. Put it on tape, into a standard TV, and it's all over. 24 bit RGB is easily accomplished, with non-encoded data and _3_ separate lines to carry it on, with a total amplitude of one volt for all the data. [continued]